Consideration Of Radiotherapy Research Articles

Radiation Therapy at the End of-Life: Quality of Life and Financial Toxicity Considerations

In patients with advanced cancer, radiation therapy is considered at various time points in the patient's clinical course from diagnosis to death. As some patients are living longer with metastatic cancer on novel therapeutics, radiation oncologists are increasingly using radiation therapy as an ablative therapy in appropriately selected patients. However, most patients with metastatic cancer still eventually die of their disease. For those without effective targeted therapy options or those who are not candidates for immunotherapy, the time frame from diagnosis to death is still relatively short. Given this evolving landscape, prognostication has become increasingly challenging. Thus, radiation oncologists must be diligent about defining the goals of therapy and considering all treatment options from ablative radiation to medical management and hospice care. The risks and benefits of radiation therapy vary based on an individual patient's prognosis, goals of care, and the ability of radiation to help with their cancer symptoms without undue toxicity over the course of their expected lifetime. When considering recommending a course of radiation, physicians must broaden their understanding of risks and benefits to include not only physical symptoms, but also various psychosocial burdens. These include financial burdens to the patient, to their caregiver and to the healthcare system. The burden of time spent at the end-of-life receiving radiation therapy must also be considered. Thus, the consideration of radiation therapy at the end-of-life can be complex and requires careful attention to the whole patient and their goals of care.

MSS05 Presentation Time: 4:05 PM: HDR Brachytherapy for Pediatric Vaginal Rhabdomyosarcoma: Two Case Reports with Long-Term Follow Up

<h3>Purpose</h3> Rhabdomyosarcomas (RMS) are the most common soft tissue tumor in children with over 400 cases diagnosed each year. Vaginal RMS is exceedingly rare, accounting for 4% of all RMS and 10% of female RMS. Outcomes are favorable with 10-year overall survival rates estimated to be over 90%. Current standard of care requires multidisciplinary approach involving chemotherapy and local therapy. To limit late effects from treatment, local therapy has advanced from radical surgeries to no local treatment in those with complete response or favoring radiation therapy for those with residual disease following chemotherapy. There is limited data on modern brachytherapy techniques for the management of vaginal RMS. Here we report two cases of pediatric vaginal RMS treated with HDR intracavitary brachytherapy at our institution and long-term follow up. <h3>Methods and Materials</h3> Following IRB approval, we identified two pediatric patients who were treated at our institution with HDR brachytherapy for RMS between 2017 and 2019 and had follow up data available. We collected demographics, presenting information, treatment data including chemotherapy, surgery if applicable, brachytherapy plans, and outcomes. <h3>Results</h3> Both patients presented at outside hospitals at the age of 2 with a prolapsing vaginal mass. Biopsies were consistent with botryoid vaginal RMS. They were referred to our institution for consideration of radiation therapy after completion of 12 weeks of VAC-based chemotherapy. Post-chemotherapy MRIs were obtained to assess extent of residual disease and a vaginal applicator was placed at the time of MRI for HDR brachytherapy planning. Both patients had good response with small areas of residual thickening along the vaginal wall. The first patient underwent exam under anesthesia, vaginal dilation and removal of visualized gross disease prior to brachytherapy. A 2.2 cm Syed obturator was used with a straight central tandem positioned at the proximal end of the obturator for central loading with 2 additional flexible catheters placed in the posterior grooves of the Syed obturator. The 3 channels allowed for coverage of the posterior and proximal vaginal disease seen on her post-chemotherapy MRI. On her last fraction, she was noted to have vaginal swelling and difficulty with inserting the Syed obturator, therefore, a 2 cm Varian single channel cylinder was used for her last fraction. For the second patient, a custom designed vaginal cylinder was made by machining a hole through a 1.3 cm vaginal dilator with a catheter inserted and affixed in the central canal. Both patients were prescribed 4.9 Gy x 6 fractions treated three times weekly with the goal of obtaining an equivalent total dose of 36 Gy with 45 Gy to the vaginal surface. The first patient was prescribed to 5mm depth and the second patient to 3mm depth based on extent of residual disease. Both patients tolerated treatment well with minimal bleeding on cylinder insertion and expected acute side effects including cystitis, dysuria and acute vaginal discomfort that resolved with sitz baths and barrier ointments. With 4 and 3 years follow up, respectively, both patients have no evidence of disease on MRI imaging and no evidence of long-term toxicities related to their brachytherapy. <h3>Conclusions</h3> Vaginal RMS is a rare cancer and thus there is limited modern experience with HDR brachytherapy as a means for local control in this patient population. Here were present two cases where devices relatively common in gynecologic brachytherapy practices can be used and customized to cover small tumors in pediatric patients. Our experience has shown that for select patients, HDR brachytherapy can be a safe, tolerable, and efficacious treatment modality for vaginal RMS.

1. Considerations for Radiation Therapy Planning from Plan/Chart Check

1. Considerations for Radiation Therapy Planning from Plan/Chart Check

Phantom assessment of three-dimensional geometric distortion of a dedicated wide-bore MR-simulator for radiotherapy

This study evaluated the machine-dependent three-dimensional geometric distortion images acquired from a 1.5T 700 mm-wide bore MR-simulator based on a large geometric accuracy phantom. With the consideration of radiation therapy (RT) application requirements, every sequence was examined in various combinations of acquisition-orientations and receiver-bandwidths with console-integrated distortion correction enabled. Distortion was repeatedly measured over a six-month period. The distortion measured from the images acquired at the beginning of this period was employed to retrospectively correct the distortion in the subsequent acquisitions. Geometric distortion was analyzed within the largest field-of-view allowed. Six sequences were examined for comprehensive distortion analysis—VIBE, SPACE, TSE, FLASH, BLADE and PETRA. Based on optimal acquisition parameters, their diameter-sphere-volumes (DSVs) of CT-comparable geometric fidelity (where 1 mm distortion was allowed) were 333.6 mm, 315.1 mm, 316.0 mm, 318.9 mm, 306.2 mm and 314.5 mm respectively. This was a significant increase from 254.0 mm, 245.5 mm, 228.9 mm, 256.6 mm, 230.8 mm and 254.2 mm DSVs respectively, when images were acquired using un-optimized parameters. The longitudinal stability of geometric distortion and the efficacy of retrospective correction of console-corrected images, based on prior distortion measurements, were inspected using VIBE and SPACE. The retrospectively corrected images achieved over 500 mm DSVs with 1 mm distortion allowed. The median distortion was below 1 mm after retrospective correction, proving that obtaining prior distortion map for subsequent retrospective distortion correction is beneficial. The systematic evaluation of distortion using various combinations of sequence-type, acquisition-orientation and receiver-bandwidth in a six-month time span would be a valuable guideline for optimizing sequence for various RT applications.

Measuring (and narrowing) the gap: The experience with attendance of Indigenous cancer patients for Radiation Therapy in the Northern Territory.

Barriers exist for both Indigenous and remote patients attending cancer care facilities. We sought to measure clinical attendance of all patients referred for consideration of radiation therapy (RT) at the single radiation therapy centre in the Northern Territory (NT), with particular attention to a comparison of Indigenous and non-Indigenous patients, and to analyse methods introduced to address the attendance of patients. Patients referred for radiation therapy over a 5year period from the commencement of the Alan Walker Cancer Care Centre (AWCCC), NT, were analysed for attendance, and for possible improvement over time. Multivariate analysis of non-attendance prior to RT (pre-RT) showed significance for Indigenous status (P<0.001), and female gender (P<0.001), and during RT showed significance for Indigenous status (P<0.001) and curative intent RT (P=0.012). Attendance during RT over the 5years showed significant improvement over time for Indigenous patients from 70.6% to 81.6% (P=0.038). There was no significant improvement with pre-RT attendance for either the Indigenous or non-Indigenous cohort. Indigenous patients experienced a lower level of attendance during RT, but this has significantly improved over the first 5years of operation at AWCCC, as recognition and management of contributing factors has improved.

Considerations in radiation therapy for pregnant women with malignancy

Treatment of pregnant women with cancer with radiation presents medical, technical, and ethical challenges. Cancer during pregnancy occurs in 1 out of 1000 cases. The most common cancers are those that are common in females of childbearing age, including breast cancer, cervical cancer, melanoma, Hodgkin lymphoma, and leukemia. The in utero radiation exposure of a developing fetus through diagnostic radiology/nuclear medicine and radiation therapy is always a concern for healthcare providers and parents. Radiation exposure to the fetus seems to be associated with increased incidences of childhood cancer at any fetal dose. However, there also seem to be threshold doses for non-cancer adverse outcomes such as intellectual disability, organ malformation, and fetal death. The fetal radiation exposure from diagnostic radiology and nuclear medicine studies is far smaller than these threshold levels. On the other hand, fetal doses from radiation therapy for treatment of maternal cancers depend largely on gestational age and distance of fetus from the treatment field. Treatment of cancers in head and neck or extremities is relatively safe, while that of pelvic organs, such as cervical cancer, is not compatible with pregnancy. It is important to note that the “threshold” doses were calculated based on observational data and therefore should be used with careful considerations in individual clinical scenarios. Ultimately, it is the frank discussion between the pregnant mother and her family with the entire medical team, including her oncologist, the obstetrician, the neonatologist, the psychologist, and the social worker, that will lead to the best individualized management plan.

Current Trends in the Management of Phyllodes Tumors of the Breast.

National Comprehensive Cancer Network (NCCN) guidelines recommend wide excision without axillary staging to treat phyllodes tumors of the breast. Without prospective trials to guide management, NCCN also recommends consideration of radiation therapy (XRT). We describe current patterns of care for the multidisciplinary management of phyllodes tumors. Using Surveillance, Epidemiology, and End Results Program (SEER) data, we identified women diagnosed with phyllodes tumors between 2000 and 2012 who underwent surgical therapy. Trends in breast-conserving surgery (BCS), nodal sampling, and XRT were assessed using the Cochrane-Armitage test. Multivariable logistic regression was used to identify factors associated with treatment. Of 1238 patients, 56.9 % underwent BCS and 23.6% underwent nodal sampling (10.5 % after BCS vs. 40.9% after mastectomy). After surgery, 15.4 % received adjuvant XRT (BCS 12.9 %, and mastectomy 18.8 %). XRT utilization increased significantly over the study period (BCS, p=<0.0001; mastectomy, p=0.0003), while nodal sampling did not change significantly. Women were more likely to receive mastectomy if they were older or had larger tumors. Nodal sampling was also associated with older age, larger tumor size, and receipt of mastectomy. Receipt of XRT was associated with later year of diagnosis, larger tumors, and nodal assessment. Over time, an increasing number of women received XRT after surgical management of phyllodes tumor, and one in four women underwent nodal sampling. While some of this practice can be attributed to concern about more advanced disease in the absence of strong data, there may be an educational gap regarding current guidelines and appropriate management.

TU‐D‐BRB‐03: Dual‐Energy CT: Considerations in Radiation Therapy

Dual‐energy CT technology is becoming increasingly available to the medical imaging community. In addition, several models of CT simulators sold for use in radiation therapy departments now feature dual‐energy technology. The images provided by dual‐energy CT scanners add new information to the radiation treatment planning process; multiple spectral components can be used to separate and identify material composition as well as generate virtual monoenergetic images. In turn, this information could be used to investigate pathologic processes, separate the properties of contrast agents from soft tissues, assess tissue response to therapy, and other applications of therapeutic interest. Additionally, the decomposition of materials in images could directly integrate with and impact the accuracy of dose calculation algorithms.This symposium will explore methods of generating dual‐energy CT images, spectral and image analysis algorithms, current and future applications of interest in oncologic imaging, and unique considerations when using dualenergy CT images in the radiation treatment planning process. Learning Objectives: Understand acquisition techniques and processing algorithms used in dual‐energy CT imaging. Discover current and future applications of dual‐energy CT images in the radiological oncology setting. Introduce some of the unique considerations and QA requirements when integrating a dual‐energy CT scanner into the radiation therapy environment.N. Pelc: GE Healthcare, Philips Healthcare, Sony; U. Schoepf: Consultant for and / or research support from Astellas, Bayer,;Bracco, GE, Guerbet, Medrad, Siemens

Follicular lymphoma: first-line treatment without chemotherapy for follicular lymphoma.

Opinion statement: The optimal initial treatment of follicular lymphoma (FL) is not known, and initial management of patients varies considerably between providers and institutions. The assertion that patients with low tumor burden can be observed for a period of time is being challenged owing to the safety and tolerability of novel therapeutics and the movement of the field away from traditional chemotherapy agents. Single agent rituximab has become increasingly popular as initial management of patients with low tumor burden disease, and there is evidence that prolonged treatment with rituximab can improve progression-free survival (PFS) when compared to induction with rituximab or observation. Radioimmunotherapy (RIT) has similarly shown efficacy in low tumor burden disease. Novel agents such as lenalidomide, idelalisib, and ibrutinib are being studied in the first-line setting. Importantly, none of these strategies have demonstrated an improved overall survival in a randomized study versus observation. It is the opinion of the authors that endpoints such as PFS alone, while important, should not drive changes in management with limited resources. Composite endpoints including quality of life are more informative on the true impact of treatments on patients with follicular lymphoma. Providers should encourage all patients to be treated in the context of an appropriate clinical trial when possible. If a patient is not a clinical trial candidate, we typically treat patients with advanced stage and high tumor burden with chemoimmunotherapy. The decision to give maintenance rituximab is individualized to the patient, as there is no overall survival benefit. In patients with early stage disease, we favor consideration of radiation therapy if the patient is a candidate. Our initial recommendation to patients with advanced stage, low tumor burden disease, is close observation or "watch and wait." We have observed that most patients become comfortable over time with an observation approach. If a patient is not comfortable with this recommendation, we will use single agent rituximab. If the patient responds to therapy, we do not recommend maintenance rituximab in low tumor burden disease but rather prefer a retreatment strategy or an extended schedule of four additional doses of rituximab.

TU‐C‐WAB‐01: Accuracy Requirements and Uncertainty Considerations in Radiation Therapy

Recent years have seen major advances in the technology of radiation oncology allowing for a transition from 2‐D radiation therapy (RT) to 3‐D conformal RT, intensity modulated RT (IMRT), image‐guided RT (IGRT), adaptive RT (ART), and 4‐D imaging and motion management in RT. Brachytherapy procedures have evolved both for high dose rate (HDR) techniques as well as permanent implants, and image‐guided brachytherapy is the modern standard. While a number of publications have defined accuracy needs in radiation oncology, most of these reports were developed in an era with different radiation technologies and date back to the 1980s and 90s. In view of modern treatment procedures, improvements in dosimetry methodologies, and new clinical dose‐volume data, the AAPM 2011 summer school dealt with uncertainties in external beam radiation therapy and the International Atomic Energy Agency (IAEA) is completing a new guidance document on “Accuracy Requirements and Uncertainties in Radiation Therapy”. This symposium will review the latest information on accuracy requirements and uncertainty considerations in radiation therapy in terms of radiobiological rationale, clinical needs and a practical reality check.Learning Objectives:1. To review historical and current data related to accuracy and uncertainties in the overall radiation treatment process.2. To provide a radiobiological rationale for accuracy considerations in RT.3. To provide a clinical rationale for accuracy considerations in RT.4. To review recent data demonstrating realistically achievable accuracy levels in RT.

Breast Cancer and Autism

Case Study Amy is a 44-year-old woman with severe autism. She lives with her sister Susan, who is her caregiver and guardian. Amy is ambulatory and able to dress and feed herself. She is a healthy individual with no other significant comorbidities. She walks daily and enjoys her sister's company. Amy's life expectancy is greater than 10 years. However, she is difficult to care for medically, as she will not allow a physical examination and strikes out when strangers try to touch her. She is nonverbal and unable to participate in decision-making. INITIAL DIAGNOSIS Amy has a history of breast cancer diagnosed 2 years ago, originally presenting as a stage I lesion (T2N0) that was palpated by her caregiver while bathing. She underwent right simple mastectomy with sentinel lymph node resection. Susan recalls that the mastectomy was a very challenging ordeal, as Amy kept pulling out IV lines, drains, and dressings. Susan felt that Amy withdrew from her after the procedure as she most likely associated Susan with the cause of the pain, making her role as caregiver more difficult. Pathology confirmed an invasive ductal carcinoma, moderately differentiated, 2.4 cm, estrogen/progesterone receptor negative, HER2/neu negative, with negative surgical margins. Two right axillary sentinel lymph nodes were negative for disease. The standard of care for a patient with these tumor features is surgery plus adjuvant chemotherapy (National Comprehensive Cancer Network [NCCN], 2012). According to the Adjuvant Online! database (2012), Amy's risk for relapse was approximately 40% without adjuvant treatment; her risk for mortality was approximately 29%. After meeting with a medical oncologist, Amy did not receive adjuvant chemotherapy. According to Susan, she was not offered the choice, and the decision was not explained to them. She was simply told that it was not necessary. Aside from pathology, previous records were unavailable for review. Medical assessment of Amy's level of autism reveals marked impairments in the use of multiple nonverbal behaviors such as eye-to-eye gaze, facial expression, body posture, and gestures to regulate social interaction. She exhibits a total lack of development of spoken language, with no attempt to compensate through alternative modes of communication such as gesture. During the visit, she occupies herself with repetitive motor mannerisms. Susan believes that Amy struggles with overstimulation from tactile input. Therefore, she is combative with health-care providers and intolerant of invasive devices. Susan has an intimate understanding of Amy's ability to communicate her needs and wants through nonverbal changes. RECURRENCE Approximately 2 months ago, Amy began favoring her right arm and appeared to be in pain when participating in various activities. Susan became aware of Amy's pain issues by noticing that her posture was slightly altered and she was carrying herself differently. Further investigation with a CT scan showed concern for local disease recurrence involving the axillary lymph nodes. No distant metastases were seen. The standard of care for this diagnosis is surgical resection and consideration of radiation therapy, followed by adjuvant chemotherapy (NCCN, 2012). Susan does not want Amy to undergo further surgery and believes radiation would be too difficult to maneuver. The next best option would be a medical approach with chemotherapy as the main modality. DIFFICULT DECISIONS If treatment is pursued, the advanced practitioner will need to perform regular examinations and prescribe and monitor chemotherapy. The delivery of therapy, requiring frequent blood draws and IV access, will be a challenge for the health-care staff. The APN is apprehensive about the ability to accomplish these tasks safely given Amy's limited capacity to participate. The APN is also concerned with how treatment will affect Amy's life. The APN may have her own individual conflict of morals to contend with, given the limited understanding of the patient vs. nontreatment of a potentially curative malignancy. Chemotherapy is not an easy task for any patient to undertake, especially for a patient with challenges such as Amy has. Although Susan can give legal consent for her sister, Amy is unable to participate in this decision-making. Susan strongly believes that Amy's quality of life is much more important than the quantity. Withholding treatment may shorten the natural course of Amy's life, yet administering chemotherapy will alter the quality of life that she now enjoys without her understanding or consent. Should Amy receive chemotherapy or should Susan refuse treatment on her behalf?

Technical Considerations in Radiation Therapy for Gastroesophageal Junction Cancer

Contemporary randomized trials have demonstrated that radiation therapy combined with chemotherapy and surgery improves survival in both the neoadjuvant and adjuvant treatment of gastroesophageal cancers. Consequently, radiation treatment planning and administration have taken on an added importance to ensure optimal outcomes as well as minimize treatment-related morbidity. This article highlights recent technical advances and considerations for radiation therapy planning for gastroesophageal junction tumors.

Epithelioid Hemangioendothelioma of the Head and Neck: Role of Podoplanin in the Differential Diagnosis

Epithelioid hemangioendothelioma is an uncommon vascular tumor of soft tissue and bone that may rarely occur in the liver, lung and the head and neck. We present five new cases of epithelioid hemangioendothelioma of the head and neck region diagnosed and managed in one institution in order to define the phenotypic characteristics, podoplanin immunohistochemical staining and the biological outcome. Podoplanin is a transmembrane mucoprotein selectively expressed in lymphatic endothelium and recently in some vascular neoplasms. The patients were comprised of two male and three female patients ranging in age from 4 to 71 years. The lesions were found in the gingiva, submandibular region soft tissue, nasal cavity and tongue, and ranged in size from 0.7 to 2.5 cm. All tumors manifested infiltrative cords and nests of epithelioid cells with occasional spindle morphology in a myxoid stroma. Immunohistochemical analysis of vascular and epithelial markers showed strong and uniform cytoplasmic reactivity for podoplanin and variable intensity and staining of CD31 and lack of cytokeratin staining in tumor cells. Surgical treatment included simple and wide local excisions. Of the three patients with follow-up, one developed lymph node metastasis and one had no evidence of disease 10 months after surgery. The patient with multiple recurrences and LN metastases was additionally treated with chemotherapy and is under consideration for radiation therapy. Hemangioendothelioma of the head and neck is: (1) a low-grade malignancy with a tendency for local recurrence and regional lymph node metastasis, (2) complete excision with negative margins is the treatment of choice for localized disease and (3) podoplanin may be useful in differentiating epithelioid hemangioendothelioma from non-vascular tumors.

Subareolar breast cancers

Background: Despite the high rate of pathologic involvement of the nipple-areola complex (NAC) with subareolar cancers and the suboptimal cosmetic results when lumpectomy removes the NAC, breast conservation surgery has been extended to include these patients. Methods: Ninety-five patients with subareolar cancers operated on between 1979 and 1998 were identified and the relationships between the pathologic findings, treatment, and outcome were studied. Results: Clinical involvement of the NAC ( P = 0.001), clinical presentation ( P <0.001, mammographic calcium or Paget’s disease), and pathologic tumor size ( P = 0.019) were significantly related to pathologic involvement of the NAC in univariate analysis. After consideration for clinical NAC involvement, no other variable was significantly related to pathologic NAC involvement in multivariate analysis. Thirty-three patients underwent mastectomy, and 62 were treated with breast conservation. Radiation therapy ( P = 0.005), clinical ( P = 0.031), and pathologic ( P = 0.037) involvement of the NAC were significantly related to local disease-free survival in breast conservation patients in univariate analysis. After consideration for radiation therapy in multivariate analysis, clinical involvement of the NAC was the only additional variable significantly related to local recurrence in breast conservation patients. Clinical or pathologic involvement of the NAC was not significantly associated with local and distant recurrence after mastectomy. No other variable was significantly related to local outcome in univariate analysis in patients treated with mastectomy. Conclusions: Subareolar cancers can be successfully treated with breast conservation surgery provided adjuvant radiation therapy is always given. Clinical involvement of the nipple-areola complex is associated with high risk of local failure when treated with breast conservation without radiation therapy.

Pediatric chest wall Ewing's sarcoma

Background: Chest wall tumors of primitive neuroectodermal origin (PNET, Ewing's sarcoma [ES]) are rare and have a poor prognosis. Multimodality therapy has improved survival results, and long-term survival is possible. Whether adjuvant radiation therapy is uniformly beneficial remains unclear. Methods: A retrospective analysis of the authors' institutional experience between 1979 and 1998 was performed. Results: Twenty consecutive patients with PNET-ES of the chest wall were identified. The median age was 12 years (range, 2.5 to 21 years). Median follow-up was 3 years (range, 7 months to 19.4 years). Seven patients presented with a mass, 12 with pain, 1 with respiratory distress, and 1 with a neuropathy. Initial therapy consisted of biopsy and neoadjuvant chemotherapy followed by chest wall resection in 12 patients. Of the remaining 8 patients, 6 underwent biopsy, followed by chest wall resection and adjuvant chemotherapy, 1 underwent biopsy, chemotherapy, and resection of a lung nodule, and 1 underwent biopsy, chemotherapy, and a laminectomy and decompression procedure. All 20 patients were included in institutional-based trials using multiagent chemotherapy. Fifteen patients received radiation therapy with a median dose of 3,000 cGy. At last follow-up, 11 patients are alive and disease free, with a median survival of 7.5 years (range, 7 months to 19.4 years). Seven of 11 (64%) survivors had neoadjuvant therapy followed by chest wall resection. Seven of 11 (64%) survivors had radiation therapy. There was no surgical mortality. Twelve patients had treatment-related complications, 3 of which were related to surgical resection. There were no survivors among patients with recurrent disease. Three of the patients who died of disease had both local and distant recurrences, 4 patients had distant recurrence only, and one patient had local recurrence only. Only 4 of 9 (44%) patients who died were treated initially with chemotherapy followed by chest wall resection. All but 1 of those that died (89%) received initial radiation therapy. All 9 patients who did not survive received additional salvage radiotherapy as well. Conclusions: Long-term survival is possible with ES-PNET after complete chest wall resection. This may be facilitated by neoadjuvant chemotherapy. Long-term survival without radiation therapy is possible, and consideration of radiation therapy should be made on a case-by-case basis. J Pediatr Surg 35:550-555. Copyright © 2000 by W.B. Saunders Company.

Identification of intermediate-risk prostate cancer patients treated with radical radiotherapy suitable for neoadjuvant hormone studies

We undertook a retrospective review of patients presenting with apparently localised prostatic carcinoma to a single practitioner for consideration of radiation therapy to clarify the characteristics of those patients who might benefit from the use of neo-adjuvant androgen deprivation. Of 133 patients referred between January 1989 and June 1994, 85 were considered suitable for radical therapy, of whom 31 were treated with hormone therapy prior to radiotherapy, frequently on the basis of an elevated PSA. Increasing PSA levels ( p = 0.0016) and Gleason grade ( p = 0.026) were independent variables for relapse. It was possible to define three prognostic groups of patients, on the basis of initial PSA and Gleason grade. Those of intermediate risk (PSA < 10 μg/l, Gleason score 8–10; PSA 10–25 μg/l, Gleason 5–7 or 8–10; PSA > 25 μg/l, Gleason score 2–4) had a superior duration of disease-free survival if given initial hormone therapy. This group of patients is potentially the most likely to benefit from such an approach and should be enrolled in prospective randomised studies of neoadjuvant androgen deprivation.

Dosimetric considerations in radiation therapy of coin lesions of the lung

The dose distribution in small lung lesions (coin lesions) is determined by the combined effects of reduced attenuation and electronic disequilibrium. The magnitude of the dose delivered also depends on the algorithm used to correct for reduced lung density. These effects are investigated experimentally and computationally for 10 MV photons. Using a polystyrene miniphantom embedded in cork or cedar, thermoluminescent dosimetry and film dosimetry was performed to investigate interface effects and the central dose per monitor unit (MU). Three frequently applied calculation techniques--no density correction, ratio of tissue maximum ratios (TMRs), and the Batho correction--were also used to calculate the dose per MU. The measurements and calculations were compared with a one-dimensional phenomenological theory with parameters taken from the literature. The measurements at the entrance surface and center of the miniphantom agreed well with the predictions of the phenomenological theory. The interface regions are usually thin enough (2-3 mm) to be clinically unimportant for 10 MV. Depending on the algorithm used to correct for decreased lung density, the lesion dose may be larger or smaller than the prescribed dose by as much as 20% in extreme cases. A clinical example is presented. In comparing clinical results of treatments of small lung lesions, it is important to be aware of the density correction used.

Visual Acuity After Successful Treatment of Large Macular Retinoblastoma

Recent trends in the treatment of retinoblastoma have favored radiation therapy as opposed to enucleation. A major determining factor in selecting radiation therapy is the possibility of useful posttreatment visual function. While the treatment of nonmacular tumors seems reasonable, little information is available about the posttreatment visual outcome of large posterior pole tumors. We treated 17 patients (20 eyes) with group III-V retinoblastoma and large posterior pole tumors with external beam radiation. Visual acuity after treatment ranged from 5/200 to 20/50. Potential posttreatment visual function was difficult to predict using such pretreatment factors as age at diagnosis, funduscopic appearance, and the number, size, and location of the tumors. Surprising visual function was obtained in some patients with multiple large macular tumors. Follow up ranged from 1 to 8 years. No patient developed metastatic disease; however, four patients required subsequent cataract extraction. This study supports the consideration of radiation therapy as the primary treatment in eyes previously felt to have a poor visual outcome.

Small Cell Undifferentiated Carcinoma of the Maxillary Sinus: Technical Considerations for Radiation Therapy

Treatment principles for extrapulmonary small cell undifferentiated carcinoma follow those established for primary lung presentations including systemic chemotherapy and prophylactic cranial irradiation. Radiation of carcinoma involving the maxillary sinus includes lateral and anterior portals which exit through the brain. Presented is a treatment strategy used for postoperative radiation of small cell undifferentiated carcinoma of the maxillary sinus in conjunction with prophylactic cranial irradiation. Specifics of dosimetry include achievement of 55 to 60 Gy within the tumor volume of the maxillary sinus, while achieving homogeneity of dose (30 Gy) within the cranial contents. Application of the described technique to analogous clinical presentations is also discussed.

Generation of iso-TDF maps: considerations for radiation therapy planning.

The NSD (nominal standard dose) concept has been useful in therapy for comparing various radiation treatment schedules. More recently, TDF (time, dose, and fractionation) factors were introduced. By incorporating treatment schedules (time and fractionation) with isodose summations, TDFs can be determined throughout the patient contour, including tissue in and outside the tumor volume. For this purpose an isodose summation program was modified to generate iso-TDF maps based on the treatment schedule. For schedules in which all fields are not treated every day, recovery is not inhibited throughout the total treatment volume. It was necessary to reevaluate the concept of "recovery time" for tissues outside the tumor volume and to introduce a "threshold to inhibit recovery" model. Clinical examples assuming this recovery model are presented.